Mobile Agents for Dynamic Multi-Hop Networks

Here at the MIT Media Lab, Nelson Minar, Kwin Kramer, and Pattie Maes have been
working on using mobile agents to route packets on dynamic, multi-hop
networks (aka ad-hoc networks). Our work has connections to active
networks and social insect paradigms. We are currently working to
apply our research to build real, flexible, low power wireless
networks for use inside buildings.

Simulated System Description

At right is a screenshot of our simulator. Nodes in the network
are drawn as squares. Green lines between nodes indicate
physical links; each node has a limited transceiver range, faintly
visible as grey circles surrounding the yellow nodes. In our
simulation these nodes are moving, so the physical links are
constantly breaking and reforming as nodes move in and out of range
with each other.

Blue circles represent routing agents travelling around the
network, red circles are message agents. The goal of the routing
agents is to update the routing tables on each node so that message
agents can find their way from any arbitrary node to one of the yellow
"gateway" nodes. Nodes in white currently have a valid route to a
gateway, nodes in grey do not.

As you can see, the three nodes in the upper left have no route to
a gateway because they are physically out of range. Three nodes in
the lower middle also do not have a valid route at the moment, because
a link they were relying on has been broken. As the blue routing
agents move to those nodes, their routing tables will be updated and
they will turn white again.

If you want to see animation, we have an applet of an earlier system
simulation.